[25stevem]

I can tell you how I did a 66 Carter AFB that might have been in even worse shape then your carb.

First to get the rear air horn screws out sit the carb up on a block of wood so it can’t rock.
Next get a tall socket that’s small enough to sit on the head of the screw ( I think I used a 5/16” ) then tap on the socket with a hammer.

This will allow you to jar the screw loose from the threads in the throttle plate.

For the next step to free up the two shafts one of the main things you will need is a electric heating pad.

If you have one then get a gallon of WD-40, a aluminum cooking pan that’s just big enough to hold the carb, it does not have to be tall enough to submerge the carb .

Next cover the heating pad with foil, set the pad on high , put the carb in the pan and pour enough WD-40 in to go half way up the carb.
Once the WD-40 gets up to about 105 degrees it will only take some 3 hours of the carb sitting in the pan to bust the two shafts free.